Fuel for internal-combustion engines.



THOMAS MIDGLEY, 33., 0F DAYTON, OHIO, 'ASSIGNOR TO THE DAYTON METAL PRODUCTS COMPANY, A COBPQRATION OF OHIO.

FUEL FOR INTERNAL-COMBUSTION ENGINES. Y

aeeassa Ito Drawing.

To all whom it may concern: 7 v

Be it known that I, THoMAs MIDGLEY, .na, a citizen of the United States of-America, residing at Dayton, county of Montgomery, and State of Ohio, have invented certain new and-useful Improvements in Fuel for Internal-Combustion Engines, of which the following is a full, clear, and exact description.

This invention relates to fuels for internal combustion engines and has for one of its principal objects the production of a cheap, suitable and practical fuel for engines of the character referred to.

Other and further objects of the present invention willvbe apparent from the following description of a fuel embodying my invention, and the methods of predetermining the requisite proportions of the component parts of this fuel.

With each of the hydrocarbon fuels nowin use, it is found that when engine compression exceeding a certain value is attained, a decided knock results. This is the well known fuel knock which is always present when the critical compression of the fuel is exceeded. 1 have found that this fuel knock is a direct function of the compression, and is always the same for the same fuel. With any known fuel, therefore, the point at which this knock occurs can be predicted. Gas en ine manufacturers have recognized this in erent characteristic of hydrocarbon fuels and have designed their engines for the available commercial fuels,'so; that knock producing compressions will not be attained.

In using the above term critical compression of the fuel I refer to the value of the engine compression beyond which one cannot go without the fuel knock resulting; and this critical compression may likewise be known as the compression value of the fuelf This limiting of compression has resulted in the loss of efliciency, since the greater the compression, the greater the explosive effect of the fuel. The special object of this invention is to provide a fuel composed of a mixture of hydrocarbons, definitely proportioned to give a fuel of any predetermined compression value, and thus a fuel with.

which any practicable compressions may be i attained, without the objectionable knock.

The proportion of the component constitu- Specification of Letters Patent.

Patented Mar. if, ieia.

Application filed January 7, 1918. Serial No. 210,687.

the desired compression value. If, however,

the compression developed in the cylinders of the engine is not definitely known, actual test must show what proportion of the component constituents isnecessary. Having once determined this proportion, any fuel of the same constituents subsequently prepared for use in that same engine, should be mixed in that determined proportion. In addition to their low compression values other disadvantages inherent in'low gravity fuels lie in the fact-that they do not start readily, especially in cold weather, and that they also cause considerable quantitiespof carbon to form in the cylinder head and on the top of the piston. Yet such fuels have the commercial advantage of cheapness, be cause of their larger quantities which are available. I

My improved fuel overcomes the objections above referred to, and at the same time preserves as far as possible the characteristics of inexpensiveness.

I use as one of the ingredients of my fuel,

for example so-called kerosene, which distils approximately between 200 F. and 560 F. Kerosene alone as a fuel would have the objectionsabove referred to, but it has the element of inexpensiveness. I have found that by the addition of a certain proportion of benzol or analogous cyclic hydrocarbons to the kerosene, T secure a blended fuel which will function even better in most respects than the best commercial grades of gasolene.

' Now, in order to predetermine the requisite proportions of benzol and kerosene, to secure the results referred to, I proceed according to the following method:

I operate an internal combustion engine such as an automobile engine adapted to attain compression of 70 to 75 pounds in the ordinary manner, but utilizing, in the fuel' tank, kerosene. Then, while the engine is running, I add gradually to the kerosene in the fuel tank, benzol in increasing amounts. When the engine is operating under the kerosene fuel, the knocking above referred to takes place. But, withthe-gradual add1-' tion of the benzol, this knocking becomes less and less pronounced. A point is finally reached where, by reason of the proportion of benzol contained in the fuel, the knocking is entirely eliminated. This point of relative proportions of the two ingredients is the proper proportion for my improved fuel. Because, while the addition of still more benzol would not be detrimental from the standpoint of knocking (since of course the knocking would still be eliminated for larger quantities of benzol), yet if an excess of benzol were used beyond the point just referred to, this would add materially to the cost due to the greater expense of benzol as Klomp'ared to kerosene.

As soon as I reach the above described point in the operation of the engine, I take from the float tank of the carbureter, a sample of the fuel as then proportioned, and test it by well known methods, to determine the proportion of benzol to kerosene. And I have found from the tests referred to that the proper proportion is substantially 50 per A proportion would be to have two separate fuel tanks, one for kerosene and the other for benzol, and have pipes leading from each supply tank into the carbureter, but with means for regulating the flow from one or the other of the tanks, (e. g. the benzol tank), so that when such flow has been regulated suflieiently to produce a combination in the carbureter to cause the engine to operate without knocking, as described, this is the desired point of proportion, which can then be determined according to the rate at which the fuels are being delivered from the fuel tanks.

Or another method would be to start with a combined fuel of kerosene and benzol in certain known proportions, and then successively try different combinations with increasing proportions of benzol until the desired point is reached.

By using the above methods, it is easy to determine the various proportions in which the constituent hydrocarbons should be mixed to give any desired resultant compression value. And tables may be prepared, showing these proper proportions. If the compression developed by the engine is known, then a fuel of the desired compression value may be obtained by mixing the desired constituents in their proper propor-.

. same as the compression developed in the engine in which it is to be used. Any excess of the hydrocarbon of higher compression value will'not detract from the anti-knock quality of the fuel, but may add to the cost of preparing it.

It may also be stated that the percentages above referred to relate to the commercial grades of kerosene now on the market. Of course, kerosene differs on the market as to its composition, some kerosene being lighter and others heavier, so that this Would have a bearing on the proportion above referred to. But this proportion may be predetermined for given grades of fuel, according to one or another of the methods above referred to.

While I have referred above particularly to kerosene and benzol as the hydrocarbons used 1n preparing my fuel, it is of course obvious that my invention is not limited to these two constituents alone. Kerosene is used for descriptive purposes merely because it is the hydrocarbon fuel of lowest compression value and lowest pricein ordinary use, and further because the results, Where it is mixed with a hydrocarbon of considerably higher compression value, such I as benzol, are especially striking. I wish it distinctly understood, therefore, that my invention covers a fuel of a predetermined compression value, composed of a mixture of a hydrocarbon having a lower compres sion value than the predetermined compression value, such for example as paraihns of the aliphatic class like kerosene, and a hydrocarbon having a higher compression value than the predetermined compression value, such for example as a cyclic compound of the aromatic class like benzol. The predetermined compression value is substantially equal to the actual compression attained in the cylinders of the engine in which the fuel is to be used. In preparing my fuel, therefore, I use constituents having compression values respectively above and below the compression value of the engine, the resultant compression value being intermediate the compression values of the two constituents, and substantially equal to the compression value of the engine.

In some instances, it may be found that slight excesses of carbon deposit will result Therefore, to remove trouble of this sort, I may add a minute quantity of naphthalene. Or substitutes for naphthalene, such as acetone, may be used for the same purpose. This, precaution may be necessary, however, only for certain types of engines.

As the petroleum products become heavier, I find it necessary to increase both the benzol and naphthalene; and conversely, with fuels lighter than kerosene, less benzol and naphthalene are necessary.

What I claim is as follows:-

1. A fuel for hydrocarbon engines of a predetermined compression value, comprising a mixture of a hydrocarbon having a compression value higher than said predetermined value, and a hydrocarbon of a lower compression value than said predetermined value, but the proportions of said hydrocarbons being such as to make the resultant compression value of the mixture substantially equal to the said predetermined compression' value.

2. A fuel for hydrocarbon engines of a redetermined compression value, comprismg a mixture of a cyclic hydrocarbon, having a compression value higher than said predetermined value, and a hydrocarbon of the aliphatic series, of a lower compression value than said predetermined value, but the proportions of said hydrocarbons being such as to make. the resultant compression value of the mixture substantially eqiial to said predetermined compression va ue.

3. An anti-knock fuel for hydrocarbon engines of a predetermined compression compression value.

value, comprising a mixture of henzol, WhlCll has a higher compresslon value than said predetermined value, and kerosene stantially '70 pounds per square inch, comprising a mixture of benzol, which has a higher compression value than said predetermined value, and kerosene, which has a lower compression value than said pre-- a determined value, the proportions of the mixture being 50 per cent. vbenzol and 50 per cent. kerosene, the resultant compression value of the mixture being substantially equal to said predetermined engine In testimony whereof I aflix my signature;

THOMAS MIDGLEY, JR.'. 

